Effects of paraquat-induced oxidative stress on the neuronal plasma membrane Ca(2+)-ATPase.

Oxidative stress leads to the disruption of calcium homeostasis in brain neurons; however, the direct effects of oxidants on proteins that regulate intracellular calcium ([Ca(2+)](i)) are not known. The calmodulin (CaM)-stimulated plasma membrane Ca(2+)-ATPase (PMCA) plays a critical role in regulating [Ca(2+)](i). Our previous in vitro studies showed that PMCA present in brain synaptic membranes is readily inactivated by a variety of reactive oxygen species (ROS).

Partitioning of the plasma membrane Ca2+-ATPase into lipid rafts in primary neurons: effects of cholesterol depletion.

Spatial and temporal alterations in intracellular calcium [Ca(2+)](i) play a pivotal role in a wide array of neuronal functions. Disruption in Ca(2+) homeostasis has been implicated in the decline in neuronal function in brain aging and in neurodegenerative disorders. The plasma membrane Ca(2+)-ATPase (PMCA) is a high affinity Ca(2+) transporter that plays a crucial role in the termination of [Ca(2+)](i) signals and in the maintenance of low [Ca(2+)](i) essential for signaling.

RNA--induced silencing of the plasma membrane Ca2+-ATPase 2 in neuronal cells: effects on Ca2+ homeostasis and cell viability.

Intraneuronal calcium ([Ca(2+)](i)) regulation is altered in aging brain, possibly because of the changes in critical Ca(2+) transporters. We previously reported that the levels of the plasma membrane Ca(2+)-ATPase (PMCA) and the V(max) for enzyme activity are significantly reduced in synaptic membranes in aging rat brain. The goal of these studies was to use RNA(i) techniques to suppress expression of a major neuronal isoform, PMCA2, in neurons in culture to determine the potential functional consequences of a decrease in PMCA activity.